1. Field of the Invention
The present invention relates to modelling a subterranean region. More particularly to computational fluid dynamic modelling of a region including a wellbore and surrounding formation.
2. Description of the Relevant Art
In the oil and gas exploration and production industry various efforts are made to assess and predict the likely flow performance from a formation. The accurate prediction of performance, particularly well inflow from the formation, helps with appraisal of development prospects, well planning and reliable prediction of true well and field value. Also, the ability to evaluate and assess the likely outcome of any specific actions associated with the well and of particular well designs will permit sensible and informed choices to be made during the design phase to ensure maximum well output.
Conventional approaches to assessing potential well performance include performing detailed appraisal operations within an established wellbore. This, however, usually requires the use of temporary completions, major in-well operations and the like which requires significant fiscal and time expenditure. Also, such in-well appraisals are restricted in that the ability to experiment with potential designs is limited as a poor test design may generate irreversible formation damage, perhaps resulting in abandonment of the well.
It is also known in the art to perform simulations of the well, attempting to evaluate virtual flow conditions and the like to provide an estimate of well performance. However, existing techniques are restricted to analytical approaches which rely on solving analytical equations derived assuming simplifications, which make it possible to obtain simple and fast answers. The simplifications made during prediction analysis based on analytic approaches are often driven by a lack of understanding of the physical conditions within both the formation and the wellbore, and take no account of the effect the creation of the wellbore has on the formation. For example, some analytical approaches simply assume homogeneity within the formation, and often ignore features associated with the wellbore and its impact on formation conditions. These analytical approaches therefore usually produce poor predictions, and are often used to identify possible general trends associated with the wellbore, rather than virtual data which is considered to accurately reflect reality.